The Effect of Mitomycin-C in Reducing Pericardial Adhesion After Cardiac Surgery in Rabbits

Background

Mitomycin-C has been in clinical use primarily as a chemotherapeutic agent and is well known for antifibrotic properties. It has been widely used to prevent postoperative fibroblast proliferation and reduce scar adhesion in ophthalmologic and otolaryngologic operations. We investigated the efficacy of mitomycin-C in reducing postoperative pericardial adhesions in a rabbit model.

Methods

New Zealand white rabbits were used and categorized into 2 groups, study (use of mitomycin-C) and control. Group 1 (n = 8) was treated with a sponge impregnated with mitomycin-C solution that was applied over the abraded epicardium. In group 2 (control group), the sponge was impregnated with 0.9% isotonic NaCl solution and was applied with the same protocol as the mitomycin-C–impregnated sponge in group 1 (n = 8). Rabbits were humanely killed at a mean of 2 weeks. The scores of adhesion were graded by macroscopic examination, and the pericardial tissues were analyzed microscopically in terms of inflammation and fibrosis.

Results

In group 1, the adhesion scores were significantly lower than the control group's. No significant difference was found between the groups in terms of the severity of inflammation. There was a difference between groups in terms of the degree of fibrosis.

Conclusions

The use of mitomycin-C to prevent postoperative pericardial adhesions reduced adhesion and fibrosis scores in an experimental rabbit model. However, efficacy in reducing inflammation was not demonstrated.     

Comparative effects of renal transplantation and maintenance dialysis on arterial stiffness and left ventricular mass index

Abstract: Background: Arterial stiffness and left ventricular hypertrophy (LVH) are major independent risk factors for cardiovascular disease in healthy and renal population. In this study, we aimed to investigate comparative long‐term effects of renal transplantation (RTx) and of hemodialysis (HD) on both arterial stiffness and LVH. Methods: Twenty‐eight RTx patients, 23 HD patients, and 20 healthy subjects were included in this prospective study. In addition to demographical and laboratory parameters, arterial stiffness [pulse wave velocity (PWV)] and left ventricular mass index (LVMi) were assessed before and one‐yr after RTx, and at the baseline and one‐yr later in HD patients. Results: There were no differences in the parameters between HD and RTx patients at baseline. PWV was significantly higher than that of healthy controls. After one yr, PWV had significantly decreased in RTx patients, but was unchanged in HD patients. Changes in PWV were significant when both groups were compared (p < 0.0001). Although LVMi significantly decreased after RTx (p = 0.02), changes were not significant between the groups. Conclusions: Renal transplantation markedly improved arterial stiffness, while it remained elevated in HD patients at the one‐yr follow‐up. There was no difference between maintenance HD and RTx groups with respect to impact on LVMi in the one‐yr follow‐up.     

Antioxidant and protective effects of silymarin on ischemia and reperfusion injury in the kidney tissues of rats

Background Renal ischemia/reperfusion (I/R) injury is a major cause of acute renal failure. Silymarin is extracted from Silybum marianum and Cynara cardunculus seeds and fruits. The aim of this study is to investigate whether silymarin administration prevents the damage induced by I/R in rat kidneys. Materials and methods Thirty male Wistar rats were randomly divided into five experimental groups (n = 6, each) as follows; control group, sham-operated group, I/R group, silymarin group, and I/R + silymarin group. In the I/R and I/R + silymarin groups, both renal arteries were occluded using nontraumatic microvascular clamps for 45 min. Then, at the end of 24 h of reperfusion, the animals were killed. Kidney function tests, the serum and tissue antioxidant enzymes and oxidant products were determined. Results Animals that were subjected to I/R exhibited significant increase in serum urea, creatinine, and cystatin C levels compared with the rats treated with silymarin prior to the I/R process (P < 0.001). The serum enzymatic activities of superoxide dismutase and glutathione peroxidase significantly decreased in the I/R group; however, this reduction was significantly improved by the treatment with silymarin (P < 0.001 and P < 0.05, respectively). Renal I/R produced a significant increase in serum and tissue malondialdehyde, nitric oxide, and protein carbonyl as compared with controls. Treatment with silymarin resulted in significant reduction in these markers (P < 0.001). Conclusion Based on our findings, silymarin protects the kidneys against I/R injury. This finding may provide a basis for the development of novel therapeutic strategies for protection against the damages caused by I/R.     

Identification of a morphometrical parameter that predicts the response to splenectomy in patients with idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is an isolated thrombocyte disease that has no correlation with other causes of clinical thrombocytopenia in adults. About 70% of patients with ITP were successfully treated by medical care and splenectomy, but nearly 30% of ITP patients do not respond to these treatments. The aim of this study is to evaluate the predictive factors that affect the success of treatment in 26 patients with ITP. Thirteen patients with ITP responded to splenectomy (responsive group), whereas 13 other patients were resistant to medical treatment and splenectomy (resistant group). The control group consisted of 13 patients who had undergone posttraumatic splenectomy. Age, sex, spleen weight, the number of follicles per mm(2), and the length of time between diagnosis and splenectomy were retrospectively analyzed. No significant difference was found between the groups with respect to these variables. Mean maximum follicle diameter (MMaFD), mean minimum follicle diameter (MMiFD), and the number and distribution of CD56 (+) cells were evaluated for each spleen specimen. There was no statistical difference in the distribution of CD56 (+) cells between the ITP patients and the control group, but the number of CD56 (+) cells was significantly higher in the control group than in patients with ITP. While MMiFD showed no statistical difference between the groups of ITP patients, a MMaFD of 350 microm and above was significantly more likely in the resistant group than in the other groups. In conclusion, this study has shown that the MMaFD is a significant predictor of the response to splenectomy.     

Sickle cell disease with regional silent cerebral infarction detected by SPECT

An 18-year-old boy was admitted to the hospital for a right leg ulcer, which appeared 1 year ago. After physical and hematologic examinations, he was referred for neurologic and cardiologic examination because his hemoglobin analysis and hematologic findings were interpreted as being consistent with sickle cell anemia. Although he had no neurologic symptoms, MRI and Tc-99m ethyl cysteinate dimer cerebral perfusion single photon emission computer tomography were performed to rule out a silent cerebral infarction. Changes secondary to an infarct were seen in the region of the caudate nucleus.     

Simulated car driving in fMRI—Cerebral activation patterns driving an unfamiliar and a familiar route

Understanding the neuronal underpinnings of cognitive processes during car driving is essential to understanding the origin of automobile accidents. Using fMRI we aimed to reveal differences in activation distribution contrasting passively observing an unfamiliar versus a familiar route to analyse the importance of the degree of familiarity of a route on attention process. We developed a special driving simulation software known as “Mechanics & Traffic”, which focuses on the physical properties of driving. Sixteen male police-academy students with special driving training were examined while passively watching the car on an unfamiliar route, following a training-period outside the scanner, and passively watching the car on the now familiar route. The driving task revealed activations in frontal, parietal, temporal, occipital lobes, the thalamus, and cerebellum. Direct comparison revealed significant activation for the unfamiliar route in the middle temporal and occipital cortex and in the cerebellum. Correlating activations with the influencing covariates of driving experience, the activation pattern was confirmed and an additional activation for the unfamiliar route was found in the inferior frontal and parahippocampal gyrus. The results give further evidence that driving a car is a complex cognitive skill. A training-period and a familiar, monotonous route seem to lead to a reduction in attention and perception processes which might be associated with a danger for commuters, even in specially trained drivers.     

Assessment of the optimal time interval and background region of interest in the measurement of differential renal function in Tc-99m-EC renography

BACKGROUND: Differential renal function (DRF) measurements are routinely corrected for background, which mainly affects the reproducibility and accuracy of the measurement. The present study was conducted to identify the most appropriate background ROI and optimal time interval in the calculation of DRF for EC renography. MATERIALS AND METHODS: Nineteen patients were studied. For determination of DRF in EC renography, the selected time intervals were 0.5-1.5; 0.5-2; 1-2; 1.5-2.5; 2-3 min, and the background ROI types were inferolateral crescent, lateral crescent, and perirenal shaped. The reference DRF was obtained through DMSA study. For low functioning kidney of each patient, relative uptake differences between the DMSA and EC scans were calculated. Then, the mean differences and the standard deviations were found. RESULTS: The highest correlation was between the DRF values obtained using inferolateral background ROI in 0.5-2 minutes of EC scintigraphy and the DRF values obtained through posterior DMSA images (r = 0.9889). However, there were no statistically significant differences between the mean DRF values obtained for each time interval with each ROI type (p > 0.05). For all the time intervals and background ROIs, the mean of the differences was <0.9%. In conclusion, in obtaining comparable DRF values from EC and DMSA studies, none of the background types proved superior. Also our research for optimal time interval showed that EC scintigraphy underestimates the DRF when compared to DRF obtained from DMSA study. The DRF has a tendency to decrease as the later time intervals are used. The time intervals less than 2.5 minutes show lower underestimation of DRF values.     

The conditions for which the geometric mean method revealed a more accurate calculation of relative renal function in 99mTc-DMSA scintigraphy

AIMS: (1) To compare the results of calculating relative renal function (RRF) by using only posterior images (POST) with the geometric mean (GM) through both anterior and posterior imaging on dimercaptosuccinic acid (DMSA) scintigraphy. (2) To determine whether there was an age-related difference between them and whether some renal pathologies or asymmetrical renal function cause an error in the RRF calculation by using posterior images only. METHODS: Eight hundred and ninety-one DMSA scans were studied retrospectively. The patients were divided into five age groups: group I, < or =2 years; group II, >2 to < or =5 years; group III, >5 to < or =10 years; group IV, >10 to < or =18 years; and group V, >18 years. The RRF of the right kidney (RKF) was calculated from the POST and GM counts. The differences between RKFGM and RKFPOST were calculated in all the patients. RESULTS: Among the 891 patients, nine had malrotated or malpositioned kidneys, 373 had renal pathologies of pyelonephritis, hydronephrosis, cortical scarring and atrophy, 247 had asymmetrically functioning kidneys and 509 had normal kidneys. When the patients were analysed according to different age groups, significant differences were found between all groups (P<0.05) except groups I-II and IV-V (P>0.05) with the F-test. The clinically meaningful RRF variance (> or =5% difference between two methods) rate differed significantly between groups I, II and III, and groups IV and V (chi-squared test, P<0.05). In patients aged < or =10 years, a clinically meaningful RRF variance (> or =5%) rate was significantly higher in the groups with pathological or asymmetrically low (< or =40% RRF) functioning kidneys than in the groups without pathological or asymmetrically low functioning kidneys, respectively (P<0.05). CONCLUSIONS: According to our findings, the calculation of RRF using the GM method differs significantly from that using posterior images. Calculation of the GM can effectively correct the RRF measurement not in only adults, but also in the patient population musical #10 years of age. In addition, a significant correction can be made in patients aged musical #10 years who have a renal pathology or an asymmetrically low functioning kidney.